Method of treating textile materials



-No Drawing.

METHOD OF TREATHY G TEXTILE MATERIALS William Julius Van Loo, In,Middlesex, N.J., assignor to American Cyanamid Company, New York, N.Y.,a corporation of Maine Continuation of application Serial No. 621,014,November 8, 1956. This application September 27, 1957, SerialNo. 686,557

11 Claims. (Cl. 117-1383) The present invention relates to the treatmentof textile materials and in particular to the treatment of textilematerials containing a major portion of nitrogen-containing syntheticthermoplastic hydrophobic materials, as for example, the nylons, acrylicfibers, and the like with certain stable thio compound formaldehydereaction products. v This application is a continuation of applicationSerial No. 621,014, filed November 8, 1956, and now abandoned.

More particularly, the present invention relates to a process forimparting a stiff, springy hand to such textile materials withoutincreasing their flammability.

Heretofore, in order to impart a stiff, Jspringy hand without increasingthe flammability of textile materials of the type specified, varioussulfonated ureaiormaldehyde resins, sulfonatedurea-thiourea-formaldehyde resinous reaction products and the like havebeen employed. Ditficulty has been encountered with regard to thestability of these materials and in many instances it has been foundthat stability for periods of time of the order of two Weeks have beenoptimum. In addition, pad bath stability in many instances was poor.Under such "circumstances, resins of these types were greatly limited intheir use.

Within limits, these problems were overcome by certain unique andinventive processes, whereby employing certain rather narrow conditionsand quantities of reactants, resinous materials were produced whichovercame the deficiency of stability recognized as a property of earliersimilar resins. These resins, however, presented certain deficiencies oftheir own. Included among them is the problem of carefully maintainingthe rather narrow conditions of the processes employed for theproduction of such resins, so as to maintain their water-soluble orhydrophilic characteristics and at the same time render them essentiallystable or at least stable for such periods of time as would notsignificantly reduce their general utility. In addition, pad bathstability with these improved resins is only fair by normal standards.

Accordingly, it is an object of the present invention to provide aprocess for treating nitrogen-containing synthetic thermoplastichydrophobic materials with a particular type of reaction product,whereby the materials so treated have an acceptably stiff, springy hand,and in addition are not more flammable than corresponding untreatedsamples.

, More particularly, it is an object of the present invention to providea process whereby nylon-containing textile materials may be treated withthe formaldehyde reaction products of certain thio compounds, whichreaction products are at least partially water soluble, and preferablysubstantially water soluble, stable, and easilymanufac tured by knownprocesses, to impart a stiff hand to the nylon-containing textilematerial without increasing its combustibility.

These and other objects and advantages are accomplished by a process fortreating textile materials contain ing a major portion of a nitrogencontaining synthetic thermoplastic hydrophobic material which comprisestreating said material with an essentially aqueous medium 2,887,408Patented, May 19, 1 959 ice StCHM nZ wherein n is from 0 to 4, and anacid acting catalyst, and thereafter curing said formaldehyde reactionproduct to a water-insoluble state.

Compounds included within the generic formula set forth hereinaboveinclude specifically the following: thiobis(formamide),thiobis(acetamide), thiobis(propionamide), thiobis(butyramide) andthiobis(valer:amide).

The stable, at least partially water-soluble, formaldehyde reactionproducts of these compounds may readily be applied from an aqueoussolution so as to impart to the fabric from about 10 to about resinsolids and preferably from about 15% to about 60% resin solids based onthe dry weight of said fabric.

They may be applied by any of the conventional means, as for example, byspraying, dipping, immersion, or the most commonly employed paddingtechnique. Thereafter, preferably the fabric is run through a microsetpadder or other similar operating device whereby the Wet pick-up of thefabric is adjusted as desired.

In applying the formaldehyde reaction products of the present invention,a suitable acid acting catalyst is employed to provide the necessaryrapid cure. Among the acid and acid acting type curing catalysts are theammonium salts, like ammonium chloride, amine salts, like triethylaminehydrochloride, alkanolamine salts, like triethanolamine hydrochloride,metallic salts, such as magnesium chloride, zinc chloride, zinc nitrateand the like, and certain free acid catalystssuch as, for example,acetic acid, adipic acid, oxalic acid, tartaric acid, and the like.Witlrrespect to the salt catalysts, these are usually emp oyed inamounts of from between 1 and 60% based on the Weight of resin solids,and preferably employed in amounts of from between 2 and 25%, based onthe amount of resin solids. With respect to the free acid typecatalysts, these are generally employed in amounts sufficient to providean application bath pH of the order of between 1 and about 3.5. Thesefree acid catalysts readily permit a low temperature simultaneous dryand cure operation without adversely affecting the tensile strength ofthe textile fabric.

The drying and curing of a treated fabric may be accomplished inseparate steps or in a single operation, if this is preferred. Whendrying is carried out as a separate step, it may be done at temperaturesranging from about 200 F. to 250 F. for from about 3 minutes to about 1/2 minutes, respectively. Generally speaking, the length of timerequired is inversely proportionalto the temperahire at which dryingand/or curing is effected. Thus, somewhat longer periods of time .wouldbe required when lower temperatures are employed and shorter periods oftime would be required where higher temperatures are employed. Thepreferred temperature and time ranges for curing of'a dried fabric arefrom about 4 minutes at 275 F. to about 30 seconds at 450 F. When dryingand curing are carried out in a single step, operation times of frombetween about 15 minutesat 250 F. to about 3 minutes at 350 F. have beenfound to be satisfactory.

As noted hereinabove, the present process is limited to die treatment oftextile fabrics comprised of nitrogencontaining thermoplastichydrophobic polymeric materials, important examples of which arethermoplastic polyamides and acrylic fibers; With respect to the former,the nylons are the important class: and with respect to the latter,acrylics, such as are-known commercially as Or-lon, Acrilan, and thelike, are intended to be included.

While the present invention is particularly adapted and effective wherethe textile material being so treated is composed entirely ofnitrogen-containing thermoplastic hydrophobic. polymeric materials, itis contemplated that the present process is fully applicable to textilematerials where the synthetic portion of it is found in a major portion,that is, in an amount in excess of 50% thereof.

In order that the present invention may be more fully understood, thefollowing examples are given primarily by way of illustration. Nospecific details therein should be construed as limitations except asthey appear in the appended claims. All parts and percentages are byweight unless otherwise designated.

EXAMPLE 1 1.5-ounce nylon twill was padded through a pad bath solutioncontaining 65.45 parts of water, 1.25 parts ofammonium chloride, and33.3 parts of a commercial fire retardant finish for nylon which is 75%solids and contains a mixture of partially methylatedthioureaformaldehyde and partially polymerized urea-formaldehyde resin.

The treated fabric was then run through a microset pneumatic padder. Thetreated nylon fabric contained 20% resin solids, based on the dry weightof the fabric. Thereafter, the treated fabric was dried and cured in asingle operation for 6 minutes at 290 F. and thereafter hand evaluationand fire retardance was determined.

The results obtained are recordedin Table I.

Fire retardance was determined; by a so-called cigar roll test in whicha portion of thetreated fabric is rolled into a cylinder and ignitedwith a match. Observations are made of the difficulty or ease ofignition of the treated fabric, rate of burning, and continued burningwhen the match is removed, in comparison to the performance of anuntreated fabric tested in a similar manner. The untreated fabric is notreadily ignited, burns slowly when ignited, and does not continue toburn when the match is removed. The overall performance of the treatedfabric was then rated in comparison to the performance of the untreatedfabric.

Hand evaluations are rendered by an operator, who compares the hand forrelative stiffness of a fabric treated according to the present processand fabrics treated with other known commercial flame-retardantcompositions, as well as an untreated fabric. The evaluations arerecorded in terms of softness or stiffness, as compared to an untreated1.5-ounce nylon twill sample, as will be apparent in Table I set forthhereinbelow.

EXAMPLE 2 This application was carried out in a manner similar to thatdescribed in Example 1, except that the treating solution contained69.25 parts of water, 1.25 parts of ammonium chloride, and 29.5 parts ofa partial polymer of dimethylol urea containing 85% solids. The treatednylon fabric contained 20% resin solids based on the dry weight of thefabric.

The results obtained are recorded in Table I.

EXAMPLE 3 This application was carried out in a manner similar to thatdescribed in Example 3 and on similar fabric, except that the treatingsolution contained 77.6 parts of water, 2.4 parts of magnesium chloride,and 20 parts of the dimethylol derivative of thiobis(acetamide)imparting 20% resin solids to the fabric.

The results obtained are evaluated hereinbelow in Table I.

EXAMPLE 5 This application was carried out in a manner similar to thatdescribed in Example 3 and on similar fabric, except that the treatingsolution contained 78.8. parts of water, "1.2 parts of2-amino-2-methyl-propan0l-l-hydrochloride, and 20 parts of thedimethylol derivative of thiobis(valeramide), imparting 20% resin solidsto the fabric.

The results obtained are evaluated hereinbelow in Table I. EXAMPLE 6Medium weight plain weave fabric of acrylic fibers commercially known asOrlon was treated in a manner similar to that described in Example 3,except that the treating solution contained 78.8 parts of water, 1.2parts of triethylamine hydrochloride, and 20 parts of the dimethylolderivative of thiobis(propionamide), imparting 20% resin solids to thefabric.

The results obtained are evaluated hereinbelow in Table I.

EXAMPLE 7 This application was carried out in a manner similar to thatdescribed in Example 6, and on the same type fabric, except'thatthetreating-solution contained 79 parts of water, 1 part'of oxalic acid,and20 parts of thedimethylol derivative of thiobis(propionamide). Thebath pH was 2.6 and 20% resin solids were imparted to the fabric.

This application was carried out in a manner-similar to that describedin Example 3 and on similar fabric, except that the treating solutioncontained 397.0 parts of water, 3.0 parts of ammonium sulfate, and 200parts of the dimethylol derivative of thiobis(propionamide) containing30% solids. This treatment resulted in an application of 10% resinsolids based on the weight of the fabric.

The results obtained with respect to hand and fire retardancy whencompared with the untreated fabric, both before and after washing, aresummarized in Table II, set forth hereinbelow. The wash reported thereinwas for 10 minutes in a 0.1% neutral soap at 100 F. in an agitatorwasher, followed by rinsing in water at 100 F. and drying in acirculating hot air oven for 15 minutes at 225 F.

Table II Test Example8 Untreated 1 m 1 it n a Stl S i. Washed S S fii.

FireIRfiitaii-dance:

n a E al..-.. St d W h Egii l st iid i As the above examples clearlypoint out, the application'of the formaldehyde reaction products ofthiocompounds 'of this invention results in substantially stiffening thehand of the treated fabric without increasing its flammability orcombustibility, and further that this treatment is durable. Theimpartation of this property to nitrogencontaining syntheticfiber-containing textile materials is of the greatest importance incertain of the applications where a stiff fabric is highly desirablecommercially. Thus, for example, fabrics ,of the type referred to hereinand more specifically nylon, find considerable usage in ladies eveningwear, such as net wraps, petticoats, and the like.

While stiffness may be imparted to nylon fabrics and garments of theclass described by the application thereto of conventional thermosettingresins, as for example, certain aminoplast resins, such asurea-formaldehyde, includ ing the cyclic ureas such as ethylene urea,1,2-propylene urea, 1,3-propylene urea and the guanamines andmelamine-formaldehyde reaction products, including the alkylatedderivatives of these species, the resultant fabric is found to be morehighly flammable than the untreated. (See Example 2, Table 1.) However,it should be noted that these and other conventional aminoplast resinsmay be employed in combination with the formaldehyde reaction productsof the compounds of the present invention, so long as the quantitiesused do not increase the flammability of treated material.

While the fabrics treated with the resinous materials of the presentinvention are classifiable as non-flammable, nettings treated withconventional aminoplast resins are classifiable as those subject torapid and intense burning, within the meaning of Public Law No. 88--83rdCongress, The Flammable Fabrics Act.

The thio compounds which are reacted with formaldehyde according to thepresent invention are a preferred group of thio compounds, because ofthe high degree of water solubility which they possess and theirexcellent stability in storage or in pad bath over reasonably longperiods of time. This is in sharp distinction over conventionalstiffening so-called flame retardant finishes referred to hereinabove.The formaldehyde reaction products of these compounds may be preparedaccording to conventional methylolation processes, which are well knownto those skilled in the art.

Thus, for example, a suitable thio compound contemplated by the presentinvention and formaldehyde or formaldehyde engendering material may beco-reacted on the alkaline side in mole ratios of from 1:2-4 or more,respectively, until the solution clears and the suitable methylolcompound is formed. Preferably, these formaldehyde reaction products areessentially monomeric in characteristic in that as such theirhydrophilic or watersoluble characteristics and stability are enhanced.However, partial polymeric materials, that is, materials which have notbecome hydrophobic or become Water insoluble, and which possess somewater solubility, are contemplated.

In the preferred water-soluble essentially monomeric form, these thiocompounds should have from between 1 and 2 moles of combinedformaldehyde. Usually, when the amount of combined formaldehyde is ofthe order of 1.7, 1.8 or greater, the material is referred to as adimethylol compound or dimethylol derivative.

While no particular advantage has been observed when the dimethylolderivatives of the present invention are alkylated or etherified, incertain instances this may be desirable, particularly where thedimethylol derivative is partially polymerized when applied, or when thethiobisdiamide is either butyramide or valeramide. In so doing, they maybe alkylated with saturated aliphatic alcohols containing from 1 to 4carbon atoms and preferably 1 and 2 carbon atoms so as to fully alkylatethe methylol groups attached thereto or partially alkylate these groups.This may be done by reacting 1 mole of dimethylol derivative with from 2to emoles ofa'satuihted aliphatic alcohol containing :from Ito 4 carbonatoms on the acid side, in accordance with procedures well-known tothose skilled in the art. It should be noted that by thetermformaldehyde reaction product as the term is used herein that bothmethylol and alkylated methylol compounds are contemplated.

If the alkylated derivative is preferred, it is employed in the presentprocess in a manner similar to 'tliafdescribed hereinabove.

I claim:

1. A process for treating textile materials containing a major portionof nitrogen-containing synthetic thermoplastic hydrophobic material,which comprises treating said material with an essentially aqueousmedium comprising an at least partially water-soluble formaldehydereaction product of a compound havingthe following general formula:

wherein n is from O to 4 and an acid acting catalyst, and thereaftercuring said formaldehyde reaction product to a water-insoluble state.

2. A process for treating textile materials containing a major portionof a thermoplastic polyamide, which comprises treating said materialwith an essentially aqueous medium comprising an at least partiallywater-soluble formaldehyde reaction product of a compound having thefollowing general formula:

wherein n is from O to 4 and an acid acting catalyst, and thereaftercuring said formaldehyde reaction product to a water-insoluble state.

3. A process for treating textile materials containing a major portionof nylon, which comprises treating said material with an essentiallyaqueous medium comprising an at least partially water-solubleformaldehyde reaction product of a compound having the following generalformula:

SlCH cONH l wherein n is from 0 to 4 and an acid acting catalyst, andthereafter curing said formaldehyde reaction product to awater-insoluble state.

4. A process according to claim 3 wherein the formaldehyde reactionproduct is essentially monomeric.

5. A process according to claim 3 wherein the compound is thiobis(formamide) 6. A process according to claim 3 wherein the compound isthiobis(acetamide).

7. A process according to claim 3 wherein the com pound is thiobis(propionamide).

8. A process according to claim 3 wherein the compound isthiobis(butyramide).

9. A process for treating textile materials containing a major portionof nylon, which comprises treating said material with an essentiallyaqueous medium comprising a water-soluble, essentially monomericformaldehyde reaction product of a compound having the following generalformula:

wherein n is from 0 to 4 and an acid acting curing catalyst in an amountsufiicient to apply from between 15 and 60% resin solids on the nylon,based on the weight of said material, and thereafter curing saidformaldehyde reaction product to a water-insoluble state.

10. A textile material containing a major portion of nylon, which isimpregnated with from 15 to 60% of a heat-cured formaldehyde reactionproduct of a compound having the following general formula:

8 ECH CONH J 3 wherein n is from 0 to 4.

sesame 2499986 Dickey et a1 May 7, 1940 8 v Hurwitz et a1 Oct. 7, 1952I-Iurwit'z et a1; Oct. 7, 1952 Reibnitz et a1 Jan. 17, 1956 FOREIGNPATENTS Canada Aug. 22, 1950

3. A PROCESS FOR TREATING TEXTILE MATERIALS CONTAINING A MAJOR PORTIONOF NYLON, WHICH COMPRISES TREATING SAID MATERIAL WITH AN ESSENTIALLYAQUEOUS MEDIUM COMPRISING AN AT LEAST PARTIALLY WATER-SOLUBLEFORMALDEHYDE REACTION PRODUCT OF A COMPOUND HAVING THE FOLLOWING GENERALFORMULA: